[Bareon]

You're thinking GirlCows, not CowGirls, see the name has the attribute attached on the front like a prefix, so whatever is in majority is placed in back like a suffix. *nods to self*
not to be confused with female cows or "Girl cows" which are both just regular cows.

Edit: Now that I think of it it could just be a different distribution pattern... uh... so you would be talking about another kind of CowGirl.. eh.. but most people want the "humanized" aspect of it all.
Oh and the udders are their breasts. *nods to self...again*